Hi folks,

I'm working on my next build with only one 360mm spot in the case (AZZA cast 808) which is an open-frame case. I know it's a bit awkward and I'm better off going for air cooling, but you know I just can't give up the aesthetics.

I don't have the hardware (4090+7800x3d) yet, and still painting the case and stuff. But I'm aiming to complete the build by the end of the year - which will have the newer series of GPUs from Nvidia/AMD. Anyway, I guess my biggest question is:

Does the radiator heat dissipation speed scale with its thickness (assuming under the same fan speed)?

Assuming I have 7800x3d and a 4090, which is around a total of 650-700 wattages of heat that I need to dissipate. On one hand, I'd want at least two 360 rads with normal 44mm thickness. But with only one 360 spot in the case, I'm not so sure if a 65mm radiator or something even thicker can do the trick.
On the other hand, since it's an open-frame case, there's no restriction from the air filter or heat build-up inside of the case. I feel like the good old "120mm for 100w" calculation shouldn't apply in my case.

So yeah Idk any more. Open to any ideas/suggestions, thanks!!

It will work, but with 300-400W from 4090 you will have large Delta T as far as water temp to ambient temp. Ideally you'd want at least one more 360mm radiator.

 

answer: external rad

 

This is the way.

 

No, its 100% not. Even with 2x 360mm rads, your not going to have the cooling effect you'd expect.

You realistically need 3x 360mm radiators to dissipate the heat from a 4090 (500+ watts) + modern day processor (300w+)

Regardless what radiator companies might claim, just assume a 360mm radiator will only dissipate 200w - 300w of power.

 

This is untrue, it depends on radiator thickness, fin density and fans/airflow.

For example my Vega LC has thick 120mm rad. It can cool 400 watts of power draw 60c/70c hotspot.

My 6900XT Toxic can cool 500 watts with 360mm thin rad like 67c/80c hotspot.

And OP mentioned low power draw CPU, I would dare to say 360mm thick rad would be enough for both. Maybe undervolt 4090 a bit for better temps. But better solution is buying air cooler for CPU and just using 360mm rad for 4090.

Assuming we targeting reasonable under 80c. Not 40c - 50c.

 

It is quite rare you’ll have a cpu pulling 300W at the same time GPU is pulling 500W unless you are for some reason running ycruncher and a gpu benchmark at the same time.

 

lol 300w CPU? The only company pulling that power is Intel, and only in stress-tests.

2x360 is fine for a 4090+14900K. I would not run CPU+GPU on a single 360mm rad, regardless of thickness, unless this was a low/midrange GPU with a light power consumption CPU.

 

I have to agree with that statement

 

Better off air cooling the 7800X3D and using the loop for just the RTX 4090. Even two 360s would make the CPU hotter than an air cooler when sharing a loop with a 400+ watt heat load.

 

I've debunked this theory. I have the 7800x3D and 3080Ti on a single 360mm and single pump (ultitube 150) and the temps of both CPU and GPU are well maintained during 4k gaming with all settings maxed (see below). Based on my experience, I don't buy this theory that multiple radiators are needed to keep the CPU and GPU cool.

https://www.overclock.net/threads/water-cooling-question-having-brain-freeze.1809741/post-29303474

 

Under a realistic gaming load the CPU and GPU might not draw much more than 500W. Nevertheless, 2x360 is not really enough if you want low fan speeds. And if you are willing to tolerate noisy fans, you might as well stick to air cooling and save a lot of money and complexity.

 

The amount of radiator surface area depends on what water temp you are comfortable with.
Water cooling's primary function is to cool water not your components.
The cooler the water the cooler your components is a by product.

Keep water temp below 35c, run it at 40+c with PETG tube and it's not gonna be a good day.

My target Water temp for a daily PC is 32c MAX after a few hours.

IMHO no a single 360 is not enough for even a 4090, I've seen my 4090 upwards of 500w not even overclocked.

 

No way. With my 7800x3d +4090 setup my room/water delta is 5C with a mora420 rad ,9xarcticp14 ) With a single 360 ur water would be 50C plus.

 

With radiators, surface area is king. Thick radiators have maybe 20% increase in performance compared to a good slim at reasonable sound levels with 10c air to water delta.

A 120x120 radiator surface area on average will dissipate 100w with 10c delta and around 1500rpm fans. Some radiators are better with high airflow, others with lower and gain less performance as the fans ramp up. THICK radiators need more airflow than thin in general.

Water temp will be directly related to component temp. Higher water temp = higher component temp. So to dissipate 600w of heat on a single 360, that would roughly be 20c water to air delta at 1500rpm+. Push/pull can help by 10-20%, but more surface area would benefit more than more thickness. If you want a quiet system, to need surface area... with an open case, you will hear anything higher than about 1000rpm depending on your noise floor. And around that that rpm, you're looking at 200-250w dissipation out of a 360 @ 10c delta.

I suggest looking over some of the data, it's a little dated but still relevant.

Radiator Review Round Up 2016 - Page 5 of 10 - ExtremeRigs.net

360 Radiator Review - hardware labs, koolance, ek, xspc, aquacomputer, watercool, water cooling, black ice, liquid cooling, phobya, alphacool, coolgate

www.xtremerigs.net

I agree that it makes sense to air cool the CPU, and only run the GPU on water if you're restricted to only a 360 radiator. Otherwise your cpu Temps will be effected by the GPU. 7800X3D isn't hard to cool.

 

I think you would have to run fans super fast in order to even have a chance.
I have been watercooling GPUs for over a decade and I have never seen an impact on a loop like my 4090 has. Even with a 360mm Corsair XR7 and a 45mm thick alphacool 480mm rad, my temps with 13900k and 4090 are not great. GPU hits mid 50's under load and I do think it actually heats up my CPU. Ive never thrown more radiator and a GPU than this and seen temps this bad. I run my fans at ~1000RPM and am pretty reluctant to turn them up any higher.

 

Ideally dual 360s or even triple rad/external rad setup like a MORA. My 5900X (100W~180W) + 3080Ti FTW3 (425-450W max load) setup is similar to your planned setup. It was struggling with a HWL GTS360 + GTS280 and only got tamed once I added a 60mm thick HWL SR2 360 MP. Even with my 3080Ti power limited to 75% (~300W) and undervolted, it will still hit 45-50C. Using 9x NF-A12x25 fans (8x rad intake, 1x case exhaust) all set to run at around 1100-1200RPM during load and 400-800RPM for idle/light loads based on GPU temps. Water temps usually hit around 36-38C max.

As others have mentioned, thicker rads may not always scale due to fin density and fans used. I opted for the HWL SR2 60mm rad since it has a low FPI and is optimized for silence/lower speed. I prefer my Noctuas to run at 1200RPM or below, but you can always run fans at much faster speeds if you can tolerate the noise.

 

Hi folks,

I'm working on my next build with only one 360mm spot in the case (AZZA cast 808) which is an open-frame case. I know it's a bit awkward and I'm better off going for air cooling, but you know I just can't give up the aesthetics.

I don't have the hardware (4090+7800x3d) yet, and still painting the case and stuff. But I'm aiming to complete the build by the end of the year - which will have the newer series of GPUs from Nvidia/AMD. Anyway, I guess my biggest question is:

Does the radiator heat dissipation speed scale with its thickness (assuming under the same fan speed)?

Assuming I have 7800x3d and a 4090, which is around a total of 650-700 wattages of heat that I need to dissipate. On one hand, I'd want at least two 360 rads with normal 44mm thickness. But with only one 360 spot in the case, I'm not so sure if a 65mm radiator or something even thicker can do the trick.
On the other hand, since it's an open-frame case, there's no restriction from the air filter or heat build-up inside of the case. I feel like the good old "120mm for 100w" calculation shouldn't apply in my case.

So yeah Idk any more. Open to any ideas/suggestions, thanks!!

The heat dissipation potential certainly scales with thickness and fin density, among other things (specifically thinness and number of tubes). But its ultimately dependent on using proper fans. For thick and dense radiators to realize their full potential, high pressure fans are a must.

Techpowerup has some good graphs to illustrate this.

Here is a 44mm radiator (EK Quantum Surface P360M Radiator) review. This radiator has 18 fins per inch, which is on the higher end of the density spectrum. Also, take note of the Black Ice Nemesis GTR 360, a 55(60)mm radiator with much higher fin density.

EK-Quantum Surface P360M Radiator Review

EK impressed before with its new Quantum Surface S360 and X360M radiators in the 30-mm and 60-mm thickness classes respectively, and today we examine the P360M that slots between the two at 44 mm in thickness. It shares more in common with the bigger X360M in features and performance too, so you...

www.techpowerup.com

Hi folks,

I'm working on my next build with only one 360mm spot in the case (AZZA cast 808) which is an open-frame case. I know it's a bit awkward and I'm better off going for air cooling, but you know I just can't give up the aesthetics.

I don't have the hardware (4090+7800x3d) yet, and still painting the case and stuff. But I'm aiming to complete the build by the end of the year - which will have the newer series of GPUs from Nvidia/AMD. Anyway, I guess my biggest question is:

Does the radiator heat dissipation speed scale with its thickness (assuming under the same fan speed)?

Assuming I have 7800x3d and a 4090, which is around a total of 650-700 wattages of heat that I need to dissipate. On one hand, I'd want at least two 360 rads with normal 44mm thickness. But with only one 360 spot in the case, I'm not so sure if a 65mm radiator or something even thicker can do the trick.
On the other hand, since it's an open-frame case, there's no restriction from the air filter or heat build-up inside of the case. I feel like the good old "120mm for 100w" calculation shouldn't apply in my case.

So yeah Idk any more. Open to any ideas/suggestions, thanks!!

The heat dissipation potential certainly scales with thickness and fin density, among other things (specifically thinness and number of tubes). But its ultimately dependent on using proper fans. For thick and dense radiators to realize their full potential, high pressure fans are a must.

Techpowerup has some good graphs to illustrate this.

Here is a 44mm radiator (EK Quantum Surface P360M Radiator) review. This radiator has 18 fins per inch, which is on the higher end of the density spectrum. Also, take note of the Black Ice Nemesis GTR 360, a 55(60)mm radiator with much higher fin density.

EK-Quantum Surface P360M Radiator Review

EK impressed before with its new Quantum Surface S360 and X360M radiators in the 30-mm and 60-mm thickness classes respectively, and today we examine the P360M that slots between the two at 44 mm in thickness. It shares more in common with the bigger X360M in features and performance too, so you...

www.techpowerup.com

View attachment 2646426

Performance increases for all radiators with the increase of fan speed but look how the relative performance increases, especually with the Nemesis GTR, going from worst performing to best performing.

Now decide how much fan speed and fan noise you want in your case and pick a radiator that will be better suited for your preference.

Having more radiators allows either better performance, or similar performance at lower noise / fan speed.

 

Had a 3080 FE and a 5900X on a 240mm without issue. Sure, temps were on the warmer side, but they were still lower than having them air cooled (and quieter, too).

 

I don't quite understand that. I'm trying to reason it out, but w/o a missing variable or two, it's not happening.

 

lol a single 360mm radiator on a 4090 would not cool it better than the 3-fan regular heatshield that comes on it. There is a distinct reason why builds that support 3 radiators put 2 on the GPU and only 1 on the CPU. The GPU produces twice the thermal output as a CPU and uses 2x the power. It's absolutely POINTLESS to put a 4090 into a waterblock just to assign a single radiator to it. You're better off leaving it air-cooled with the vapor chamber.

It would, again depends on density and on airflow. GPUs have big dies which means it's fairly easy to transfer heat into cold plate. GPU doesn't necessarily produce twice the thermal output as CPU would nor it necessarily uses twice as much power. OP mentioned wanting to get 7800x3D which generally pulls low amount of power.

Thick and dense 360mm rad would still be better than any air cooler on 4090. If it was such a bad idea there wouldn't be that many 4090s with 240mm AIOs. Your argument only makes sense if you are assuming that OP would overclock 4090 to 700 watts. Then yea single rad doesn't make sense at that point. Or that GPU must run a lot cooler than 80c on full load. Then yea, one rad wouldn't be enough.

I don't see the point of watercooling if you are merely going to replicate the performance of the stock air cooler. With a decent waterblock GPUs should run below 50C...

OP mentioned having limited space in the case. Of course I would say it would be better to have multiple radiators but if there is no space 360mm thick and dense radiator would do the job. I dare to say single 360mm rad would handle 4090 and have lower temps / less noise compared to air coolers. Although 4090s do have pretty good air coolers usually.

 

I keep looking at the thread title thinking that "THICC" is a new brand available on Alibaba.

 

Had a 3080 FE and a 5900X on a 240mm without issue. Sure, temps were on the warmer side, but they were still lower than having them air cooled (and quieter, too).

5900X is a quite different scenario; it's twice the power of a 7800X3D, but lower die-to-coldplate thermal resistance and lower thermal density.

If the water in a loop in more than 5C or so above ambient, and the block isn't one of the top performing AM5 blocks, a 7800X3D will be at least as hot underwater as with a $35 air cooler (something like a Thermalright PA or Phantom Spirit) and rational airflow.

A watercooled 4090 will run much cooler than with largest air coolers, even with modest rad area and a ~20C air to water temp delta. Sticking a low-power, but temperature sensitive processor into the same loop means you need to add a huge amount of radiator area that wouldn't otherwise be needed if the parts were kept separate. Coldplate/coolant temps are everything for the X3D parts; they barely produce any heat of their own, but what they do make is damn hard to remove.

In a 7800X3D + RTX 4090 loop, the CPU is less than 20% of the heat load while gaming. Core temperature deltas will always be high with a 7800X3D, which is why the coolant (or heatsink base) has to remain as cold as possible. Setting a loop up to maintain target delta T, with five times as much heat as you'd otherwise need to move, radically increases the radiator area required. ~15C delta T (what you can get with a 240 rad at moderate noise levels, or a near silent 360 rad) is fine for a 4090...cooling it further will add almost nothing to performance and migh even result in regression in stable GDDR6X clocks. ~5C delta T is achiveable on a 7800X3D while gaming with a 120mm radiator. ~5C delta T in a combined loop (450-700w total, depending on what one does), without having the system sound like a hurricane, is triple, or even quad, 360 territory.

I'm pretty sure a waterocoled RTX 4090 paired with an average pump, an average 360mm radiator, and average fans, would generally trash even the best GPU heatsink.

Easily, but at coolant temps that would result in very suboptimal performance for a 7800X3D in the same loop.

I have a 4090 FE setup in a friends rig in a LanCool 3, and don’t see above low-mid 60s on the core. Don’t remember the mem junction temps. For an aircooler trying to tame 450w+, I think it does pretty damn well. 🤷🏼‍♂️

The FE cooler isn't bad in absolute terms, but it's worse than almost every other 4090 air cooler, even among cards that had the same MSRP. And the absolute best 4090 air coolers are only competitive with a slim 240mm radiator.

 

lol a single 360mm radiator on a 4090 would not cool it better than the 3-fan regular heatshield that comes on it. There is a distinct reason why builds that support 3 radiators put 2 on the GPU and only 1 on the CPU. The GPU produces twice the thermal output as a CPU and uses 2x the power. It's absolutely POINTLESS to put a 4090 into a waterblock just to assign a single radiator to it. You're better off leaving it air-cooled with the vapor chamber.

I disagree about it being pointless to assign 1x radiator to the 4090. I have a dual loop with a 480 on the 7950X and 560mm on 4090 TUF OC. The GPU temps do not get to 50Cs during gaming and are typically around the mid 40s during 4K gaming (all settings maxed) and may hit 50C during 4k benchmarks. FarCry 6 constantly hits 750-800w. Hell, I've seen FarCry NewDawn peak at 900w. My UPS is constantly screaming (need to get larger capacity unit). BF3 multiplayer gaming temps sit around the mid to upper 30Cs. This is not based on theory but real life.

 

With this guy's specific case and the fact that those particular AMD CPUs have such a hard time having the heat removed and are temperature sensitive... Maybe it would make sense to have the cooled water from the radiator go through the CPU first in this use case? Usually I don't think it makes much of a difference. But maybe in this case it would. If you do go with a thick radiator, be sure to use fans that are designed for static pressure. I personally think you would be ok, but do not expect to see 50c on your components all the time especially if your room is hot or you have workloads that leverage both the CPU and GPU simultaneously. However, there really is only one way to truly find out... Please let me know if you ever build the system I am curious to see how it turns out.
P.S. I bet you could make it work if you aren't fully happy with your temps / noise if you are willing to put in extra work by a good undervolt on GPU or CPU or both.

 

I have the 5000D case with an EVGA 3080Ti Hydrocopper CPU (pulls 400w) and the 7800x3D (pulls around 80w or so) on 1x 360mm radiator. I game with a 4k monitor and the radiator is HWlab Nemesis 360GTS XFlow (see other build specs below). Cinebench benchmarks temperature for the CPU peaked around maybe 80c and average temps were in the 70s. Superposition and the Heaven benchmarks temps did not exceed 52C. Playing Far Cry 6 for over 4 hours with all Ultra settings, 4k, HD package and ambient temps around 30C and the GPU temps peaked at 55C but average in the high 40s, while the CPU temps peaked at around 72C but average lower. The GPU was running around 100% and the CPU around 76% during the gaming session. I was able to get the temps down another 3* when I ramped up the pump speeds from 50% to 100%, but satisfied at 50%. Based on my experience using 1x radiator to cool both the GPU and CPU, I am not a believer that you need tons on radiators to cool these components.

https://www.overclock.net/threads/water-cooling-question-having-brain-freeze.1809741/post-29303474

 

hello,
i have real overkill cooling on my set up.
i have got over a long time and found most most of it from a bargain bin sale, XSPC™ Raystorm™ 360 kit for £120 instead of £180 (about 10 years ago), so i brought another radiator from the bargain bin.
the bargain bin is a good idea as you can still return for 3 months and its a copper lump and a pump that cant overheat in my kit.
2 x XSPC™ D5 pumps in to one loop, both radiator are XSPC™ EX360 x 35 externally mounted and have Noctua™ F12 3000rpm fans in pull only.
at present i have a AMD™ Ryzen™ 7 3800XT and a Sappire™ AMD™ RX7900XTX Nitro+.
its the CPU that is the hottest item in my loop.
my MSI™ AMD™ RX Vega 56 crossfire was the same, cpu is the hottest item.
going to update the CPU waterblock soon and see if it can get it to cool down a bit, but its fine at around 60-70c.
the gpu is down at 50c.
as to whether a single 360 radiator would be enough, i do not know.
but if you do go for a extra thick radiator i would head to push and pull config.
Best regards,

 

Noctua’s at 2K are absolutely loud lol.. I get that it’s subjective to the ear, how far away the PC is, etc.. but 2K is high RPM.

Open-back headsets do not filter any noise either, and open-back provides a wider sound-stage; preferable for gaming.

I don’t know what proof you need. It’s like asking for proof of the earth rotating the sun — these are established facts and methods that have been known for years. The more surface area you have, the lower fan speed you can run to achieve the same thermal performance.

With 2x 480 Heatkiller-S and 1x 360 Heatkiller-L, with fans at 950-1050rpm (staggered to break up the fan noise synchronising), my WaterT peaks at 32c in a 24c room, with a 4090 pushing 450-500w and a 14900K pushing 120-150. RAM is in the loop too, but negligible wattage added.

 

Don't tell me what your temperatures are...show me. All you have to do is play a game (a game that work the component(s)) for 1 hour and post the results from HWinfo that shows all the data. That's not asking proof of the earth rotating the sun; just facts to back up your claim you posted above. This is a simple task. Prove it. That's all I ask. If true, I will be a believer. As of now, I don't believe it.

As a retired Auditor my MO during my Auditing years was you can tell me anything, but you can only show me the proof. Just show me and shut me down.

 

as i said in another thread, checked my Noctua™ NF-F12 3000rpm's on 0rpm state, last recorded rpm was 230rpm, that's a quiet setting alright.
i ran some Cooler Master™ 1200rpm case fan on my rads once, it was fine and unreasonably quiet.
i am just stressing CPU with CPU-Z™ 67c and changed the fans at 1200rpm, the temps stayed the same and then dropped by 1c.
you have loads of room for quiet, about 20-30c worth.

 

You can cool almost anything with a single radiator, Everything revolves around water temp (your ambient matter's a lot as well).
Water temp is KING!
People look at water cooling in the incorrect way as in only looking at the component temps, I look at water cooling this way. I use water cooling to cool water, I get the added benefits of my components being cooler.
The more radiators you have to longer you can sustain the wattage you are trying to dissipate, we can add more rads and there will be a point to where water temp will stop decreasing "but" we will be able to maintain that minimum water temp for a longer period of time.
Now a single Radiator with a 4090 and a CPU, yes will work just fine "if" you are comfortable with the water temp's being over 40c.
Me personally my target water temp is and will always be 30c, a D5 pump is rated to a max of 60c and I have seen PETG start to deform around O-rings/ferrules in the mid to upper 40c water temps.

So the real answer here is yes a single radiator will work, you just have to decide what water temp you are comfortable with. If you want the water temp as low as possible with a single radiator you are gonna need some pretty serious fans to help.

My setup I run a MO-RA 420, 9 Artic P14's that never go over 900RPM while gaming for hours on end.